The application of iron tailing powder to concrete as a mineral admixture is conducive to high value utilization of solid waste and energy saving and emission reduction. However, most studies on the durability of iron tailing powder concrete only consider single conditions or accelerated conditions, and its deterioration characteristics under multiple environmental coupling have not been explored. In this paper, the relative dynamic elastic modulus and mass loss rate are used as performance indexes to study the deterioration process of iron-tailing powder concrete under load-wet-cycling-sulfate coupling, and explore the influence of iron-tailing powder content and load rate on the internal deterioration of iron-tailing powder concrete. By means of scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and mercury injection (MIP), the damage and deterioration mechanism of iron tail powder concrete under coupling action was revealed. The results show that the application of load increases the width and number of microcracks inside the test block, and the continuous calcium dissolution results in the increase of slurry porosity and the formation of more connected channels. The coupling effect makes the internal damage of iron tail powder concrete accumulate continuously, which is manifested in the porosity of structure and the derivative expansion of cracks on the micro level, and the attenuation of mechanical properties and the decline of the overall structural integrity on the macro level.